Pump



April 25, 1939. F. E. STELZER PUMP Filed Nov. 5, 1955 6 Sheets-Sheet l 5 y .5 /7 f x a2 4 /7 fl //Z 5 W /a a a 30 & A; 9

April 2 1939- F. E. STELZER 2,155,452

PUMP I Filed Nov. 5, 1935 s Sheets-Sheet 2 f if April 25, 1939.

Filed Nov.

F.E.STELZER -PUMP 6 Sheets-Sheet 5 April 5, 1939. F. E. STE-LZER. I 2,155,452

PUMP Filed Nov. 5, 1935 v 6 Sheets-Sheet 4 06M MM A ril 25, 1939.

F. E. STELZER PUMP Filed Nov. 5, 1935 6 Sheets-Sheet 5 April 25, 1939.

Filed Nov. 5, 1955 F. E. STELZER PUMP 6 Sheets-Sheet 6 1 tice which are illustrated and described herein;

Patented Apr. 25, 1939 UNITED STATES PATENT OFFICE,

Frank E. s n-firms, N. Y. Application November 5, 1935, Serial No. 48,411

10' Claims.

This invention relates to centrifugal pumps and has for its general object the provision of the compression of the gaseous fluid. The invention also contemplates the provision of cer- 10 tain installations by means of which the pump may be made to effect the purposes set forth.

A more particular object of the invention is to provide in such pumps impellers of novel and improved constructions designed to centrifugally project the denser one of the fluids being pumped through restricted orifices so as to draw the other fluid along with it in much the same manner as that of an ordinary aspirating pump, injector or the like.

It is also an object of the invention to provide novel pump casings adapted for the reception of such impellers and for. the control of the flow of the fluids entering and leaving the pump.

Other objects include the provision of certain accessory devices rendering the several pump embodiments adaptable to a variety "of uses.

These include certain novel casing, tank, and conduit arrangements which constitute the preferred examples of the reduction of my invention to prac- These illustrative examples'comprise installations 'for the operation of vacuum steam heating systems, steam condensing pumps, self-priming suction pumps, fluid mixers,

be apparent from the when read in connection drawings, in which sewage ejection systems,

following specification with the accompanying Figure 1 is a. vertical transverse sectional view of a pump unit embodying the principles of my invention, the lineof section being substantially that indicated at 1-1 in Figure 2, but passing between the blades or vanes of the impeller for the sake of clearness of Figure 2 is a vertical se illustration; ctional view of the pump taken'on a plane perpendicular tothat of Figure l as indicated by the line 2-4 in that figure;

Figure 3 is a partial sectional view'taken-substantially on line- 3'3 of Figure 2;

, Figure'4 is a partial sectional view taken stantially on line 4-4 of Figure 2;

sub-

Figure 5 is a partial sectional. view showing'a modification in the air casing} intake portion of the of a pump installation embodying the principles 5 of my invention and adapted for use-in connection with a vacuum steam heating system; two identical pumps capable of being used in connection with a doubletank provided with means for separating and controlling the flow of the feed water and condensate;

Figure 8 is a vertical transverse sectional view of one of the pump units, the tank being shown in elevation rearwardly of the pump;

Figure 9 is a view in elevation of the tank, 16 a portion thereof being shown in section as taken on line 9---9 of Figure 14, this view'also indicating diagrammatically the automatic controlling means for the pump motor;

Figure 10 is a view in vertical section taken through the pump and one-half of the double tank, substantially on lines Ill-l0 of Figures 8 and 9, and indicating the construction of the alternative single tank to beused with only one pump; I a

Figure 11 is a partial vertical sectional view taken through the tank line il ll of Figure9;

Figures 12 and 13 are similar views taken on lines l2-I2 and l3-i3 respectively of the same figure; f l

Figures 14 and '15 are partial views in horizontal 'section'taken through the tank on lines 14-14 and 15-45 respectively of Figure 9;

Figure 16 is a view of the tank in vertical section taken on line 16-16 of Figure 14; N

Figure 1'? is a view in vertical section of an i embodiment of my invention adapted for use as a fluid mixer, a self-priming centrifugal pump, or the like; l

Figure 18 is a' viewpartly in elevation and 49 J partly in vertical section of an installationadapted for use as an air pump in a variety of capacities, such as,-for example, in connection with the sewage ejector illustrated 'in elevation in Figure I 19; and i Figures 20 and 21 are'longitudinalsectional views illustrating certain arrangements of single suction impellers for use in existing pump casings or in especially designed installations. v

'In the first five figures of the drawings there is illustrated a double suction pump which constitutes a preferred embodiment of my invention and which may be 'e loyed without substantial alteration in many of the installations described and suggested herein. The pump casing indiu cated generally by the reference character is preferably divided horizontally into an upper section H and a. lower section 12, suitable sealed connections being made between the connecting flanges at l3. Any suitably formed base or pedestal portion may be provided as at l4. The two sections of the casing ID are shaped to provide a central impeller chamber l5 which is of a volute configuration and preferably is formed with its side walls converging toward the periphery thereof so as to provide a sort of V-enturi effect in cooperation with the aspiratory impeller which will presently be described. Spaced laterally from the which cooperate certain sealing rings and portions of the impeller to provide inlet chambers v centrally located impeller chamber l5 the casing is formed with annular enlargements IS with with a suitable motor. Preferably bearing sleeves 23 are provided at the ends of the impeller and form substantially extensions of the hub thereof. Suitable packed bearings or stumng boxes 24 surround these sleeves and provide sealing means between the pump casing and.the rotary portions of the pump. Centrally of the pump the hub 2| of the impeller is provided with the streamlinedenlargement 26 upon which are formed the curvedradi'ally extending vanes or blades 21,

these vanes 2'l-being bounded laterally by the shrouds 28, forming thebuckets' of the impeller. The shrouds 28 are extended'axially of the pump to form the tubular walls 29 of the impeller. These walls 29 are provided with flanges or seats for thesealing and bearing rings .30 which are also seated in suitable grooves formed in the easing and serve to separate the air inlet chambers indicated at Hi from the impeller chamber l5 of the pump. Similar sealing and bearing rings 32 are provided between the air inletchamber l5 and the water inlet chambers i1, these rings being seated appropriately in the casing wall and also provided with a seat 33 forming a bearing for the impeller 20.

The radially enlarged central portion of the impeller is provided with the spaced partitions I5 which intersect the vanes 21 and are continued axially to form the tubular portion 36 which eventually merges. with the outer tubular portion 29 of the impeller adjacent the end seat or shoulder 33. .-It will be noted that these tubular portions. 38 of the partitions divide the end portionsuof the impeller into annular air and 'water inlet conduits da'ignated respectively by the reference numerals 39 and 4', the conduit 39 being placed in communication with the air inlet chamber l6 of the casing as by means of the openings II and the annular conduit 40 communieating with the water inlet chamber I! through the center ofthe outer'sealingring 32 as at 42.

It will be further'noted that the radial portions of the partitions extend only a short distance outwardly between the shrouds 28 13min hating at the point'45 "to "form with the vanes 21 a series of smaller inner-buckets the peripheral openings of which-maybe considered as propelling peller between the shrouds 28 and the partitions 35. Thus, by combining the aspirating and centrifugal effects, both fluids may be effectively mixed and propelled through the volute cham ber 15 and thence outwardly through the common outlet provided, in this instance, in the upper casing portion ll.

An intake connection 52 for the water or other propelling fluid is provided in this case in the lower casing portion I2 and'is divided as at 53 into two laterally extending passageways 4 which provide communication with the water inlet chamber H. An air or other aspirated fluid inlet connection 55 is similarly divided as at 50 to provide the lateral passageways 51 each leading to one of the air inlet or aspirated fluid chambers I6. By-pass passageways 58 are provided in the casing between the chambers 16 and H and are adapted to be controlled by suitable valves or plugs suggested at 59. In Figure 5 there is illustrated an alternative form of air intake which may be employed in some installations in which the air is introduced through a lateral opening 60 and is conducted into the air inlet chambers l5, which lie between the water inlet chambers I 'l' and the central impeller volute chamber l5.

In cases where it maybe desired to aspirate different fluids through the two sides of the pump, two of the air inlets such as indicated at B0 in Figure 5 may be. provided,' one on either side of the casing and a partition indicated in dotted lines at 62 may be formed in order to sep- 'arate the two inlet chambers I6 .on either side of the pump. In some installations this arrangement may bedesirable when it is necessary to pump air or vapor on one side of the casing and steam condensate, for example, on the other.

A diffusion vane indicated at 65 in Figure 2 may also be inserted in the outlet 50 of the chamber IS.

The stufl'ing boxes 24 provided in the casing I for the accommodation of the rotary drive shaft compress air or other gaseous fluids, a circu latingbody of water or otherliquid may be maintained in the pump and a suitable return system which will preferably include a separate ing tank. This body of denser fluid being thrown through the inner series 'ofbuck'ets or "nozzles 1 at- 45 will effectivelyaspirate the air through the outer buckets of the impeller between the shrouds 28 and partitions 35, through the'mixing chamber portions 48 of 17- outer buckets, the volute chamber I5, and thence through the. outlet 50 into a suitable separatory chamber and into a suitable container for the compressed.

fluid. Alternatively, the pump may be employed as a mixing device for difierent fluids, both be ing liquid or one of them liquid and the'other gaseous as in carbonating processes, the fluids 5 p 2,155,452 I being admitted separately into the inlet chambers I6 and I1 and then mixed and ejected by the impeller as described. The use of the pump as a steam condensing pump will be readily understood, the condensing water being passed through the propelling or aspirating system 52,

'54, I1, 40, 45, 48, etc. and the exhaust steam being admitted through the propelled fluid system 55, 51, I6, 39, 48, etc. Vacuums may be produced by connecting the air inlet 55 with the space to be evacuated and circulating a body of 7 water or other aspirating medium through the proper channels. The pump, of course. may be employed in various other installationsfor example, for agitating different kinds of liquids or washing and cooling gases.

In Figure 6 of the drawings there is illustrated a modified type of impeller which is adapted to perform the double duty of pumping a single fluid through one portion of a suitable casing and propelling two fluids in aspirating relation in another portion of the casing. The aspirating side of the impeller is substantially the same as one side of the double suction impeller illustrated in the first five figures of drawing. The impeller designated generally by the reference numeral I0 is provided with a central bore through which a drive shaft II is adapted to pass, suitable keys beingprovided for rigidly' mounting the impeller on the drive shaft. Upon the left hand side of the impeller there is provided an ordinary centrifugal rotor portion I2 having vanes 13 bounded by the outer shroud I4 and the inner shroudor partition 15, the buckets bounded by the vanes 13' and the shrouds I4 and 15 being curved along with these members to provide an axial center inlet shown at 11. A guidewing or flange I8 may be provided on the inner wall or partition 15 to interlock with a suitable groove in the casing, or in the diaphragm sealing ring 19.

' The right hand portion of the impeller is provided with the blades or vanes 8i bounded bythe outer shroud 82 which is quite similar in figuration to one of the shrouds 29 of the previously described embodiment having portions 83 and 84 shaped to cooperate with. sealing and bearing rings just as in the other embodiment. A partition 85 divides the buckets of this portion of the impeller into two parts, an inner series 81 for the impelling fluid which passes axially through the inner annular passagev iy 88 and the portion 89 forv the aspirated fluid which passes through the conduits 90 which are in communication through the holes SI with one of the intake chambers of'the pump. This embodiment finds probably its greatestutilization in connection with vacuum steam heating systerns, one of which comprises an important feature of the present invention, and will be described in considerable detail herein.

In Figure 20 there is illustrated an embodiment of the double impeller arrangement which maybe employed incertain existing pump castings or-in especially designed housing. In th s arrangement 't-hesingle suction pump impeller portion 80 is carried by the drive-shaft II and is spaced any desired distance along the shaft from the separately formed centrifugal pump impeller portion I0. These separately formed impeller sections are substantially identical with their corresponding integrally formed embodiments shown in Figure 6 and the various. elements thereof will be given the same reference characters.

In Figure 21 of the'drawings the single suction impeller 80" is shown alone on its drive shaft-II" and is provided with the same vanes, passageways and apertures which are shown and described in connection with the preceding embodiments. This impeller may be employed for the same purposes described in connection with pump.

Figures 1-5 of the drawings but wherein a of less capacity is desired.

The pumping installation forming a part of a vacuum steam heating system and comprising another embodiment of the principles of my invention is illustrated in Figures 7-16 inclusive of the drawings. In Figure 7, which isa view in elevation of a double pumping arrangement, the two pumps are indicated at A and B and a double condensate receiving and separating tank is indicated at C. For systems of smaller capacities a single unit may be employed comprising one of the pumps,say pump A,-and only half of the tank C, the double tank ,C being exactly symmetrical upon either side of the center line :c-x. In

' this case, the left hand side of the tank will be provided with a solid wall along the plane of the line a:'a:, and certain minor alterations and adjustmentsbeing effected in the condensate and valve connections, as will be hereinafter described. In connection with most of the figures of drawings, only one side of the double arrangement shown in Figure 7 will be described, it being understood that this much of the device can be employed in smaller systems, and in order to double the capacity of the pumping arrangement the device has merely to be duplicated upon the opposite side of the lines a::c appearing in these figures.

The pump unit employed in these connectionsing means, stufling boxes I 03- being provided for the impeller drive shaft I04 passing through the pump. The pump casing is also provided with spaced anti-friction bearings I05 for the drive shaft carried by the brackets I06, these bearings comprising the ball-bearing assemblies I01, andassociated sleeves and packings. The shaft is adapted to be driven by a suitable motor, a por; tion of which is indicated at I08 in Figure 9, in which figure there is also diagrammatically shown certain automatic controls for the motor which will be described at the proper place hereinafter.-

The impeller in this pump is of exactly the same construction as that'designated 10 in Figure 6 of the drawings and the same reference characterswill be used to indicate the various parts in these figures. The light hand aspiratory section 80 of the impeller is employed to withdraw the condensate and air from a portlonof the receiving tank C by utilization of a bodyof priming or propelling. water which is always maintained at a substantially constant level in a certain portion of the tank and in the pump casing, this level being indicated by the line y.y in certain figures of the drawings. ,The priming or propelling water chamber of the pump casing'is'indicated .at'

0 of the drawings and corresponds to the 'simi larchamber H in the earlier described figures.

This priming water intake chamber H is connected with the tank by means of the conduit I II which may be placed in communication withthe tank opening H2 by means of the valve H3. The condensate chamber H5 is provided in the casing adjacent the priming water chamber H0 and separated therefrom by means of the ring H6 which provides a sealing means for the portion of the propeller 10. The condensate or propelled fluid chamber I I5 is placed in communication with the tank C by means of a suitable conduit H9 communicating with the opening I in the tank. Another bearing ring I22 is provided for sealing off the condensate intake-chamber H5 from the volute impeller chamber I25 and cooperates with the bearing flange 83 of the impeller. The annular passageway 88 surrounding the impeller shaft I04 provides means for transmitting the priming water from the intake chamber H0 to the inner buckets 81 of the impeller. The condensate fluids pass from the intake chamber H5 through the openings SI and thence through the annular passageway 90 into the outer bucket portions 89.

The priming water acts as an impelling or aspirating fluid being delivered from the inner buckets 81 through the mixing zone I26 between the'point of termination of the partition'85 and that of the shroud 82. The priming water is thus made to aspirate the condensate fluid which may consist of water, air, or uncondensed vapors, and propel both fluids through the volute impeller chamber I25 into the outlet conduit I28 from which it passes into the opening I 29 in the cupola or dome section I30 of the tank C and thence into certain compartments of thetank which will be described.

, supplies the heating system. This feed water issues from the opening I32 of the tank and thence through the conduit I33, controlled by the valve I34, into the feed water intake chamber I36 of the pump casing. The left hand portion 12 of the impeller comprising the centrifugal pump rotor is disposed within the impeller chamber I38 and serves to centrifugally propel the feed water from the intake chamber I36 through the chamber I38 and thence outwardly through the discharge passageway I39, thence through the opening I40 in the dome I30 and through certain com partments therein to the boiler.

Thus far it has been explained how the pump receives priming water and condensate fluid from the tank C and utilizes this priming water as a propelling or aspirating medium to withdraw the condensate fluid from the tank and discharge the mixture into another portion thereof. As will be liquid medium being re-used as priming water and the excess being supplied to the boiler feed compartment, the air and separated vapors being vented to the atmosphere. It has also been explained how the pump in its dual capacity with-' draws feed water from the appropriate compartment in the tank C and supplies it through another portion of the tank to the boiler.

The tank C thus serves to receive the condensate fluids from the vacuum heating system; to retain a quantity of priming water at the necessary level to prime the pump; to provide a reservoir for the boiler feed water; to provide means for separating the air and vapors from the condensate fluid and priming water mixtures; and to provide certain conduits for the admission and delivery of these various supplies of fluid. Communications are provided between these various compartments where necessary and bafiies and valves are arranged in the tank to maintain the required levels in certain of the compartments and to prevent syphoning of the residual fluids, all as will be hereinafter described in detail.

The tank C is provided with an inlet opening I near the bottom thereof which is connected through the check valve I5I and the screen I52 with the return main of the heating system, a portion of which is shown at I53 in Figure 8. From the opening I50 the condensate liquid from the system passes through the low horizontal passageway I55 and from thence it rises upwardly in the vertical compartment I56 to the level y-y, whereupon it may flow in two directions, namely, forwardly over the baffle wall I58 and thence downwardly through the spring pressed check valve I59 into the compartment I60 and also laterally over the baiile wall I 6I through the opening I62 into the vertical compartment I63. The condensate under the proper running conditions of the pump is withdrawn from the chamber I60 through the outlet opening I20 and into the condensate chamber H5 of the pump as already described.

The necessary supply of priming water is retained in the compartment I65 of the tank, this chamber or compartment I65 having the forward- 1y disposed downwardly extending leg I66 from which the priming water is taken through the opening H2, valve H3, and conduit III to the priming water inlet chamber H0 of the pump.

The priming water chamber I65 has a horizontally extending portion I61 which overlies. both of the condensate compartments I56 and I60. 'The mixed priming water and "condensate return through the conduit I28 from the right hand outlet of the pump A passing through the elbow I68 back into the upper portion of the priming vwater chamber I 65 through the opening I68. Suitable air vents may be provided in the top of the priming water chamber I65 to permit the escape;

which obtains its supply of water from the overflow of the priming water chamber I65 through the openings Ill. The feed water chamber I10 is provided with a forward downwardly extend ing leg I12 from which the outlet I32 leads through the valve I34 intothe inlet chamber I36 of the left hand side of the pump A. The feed water is propelled through the outlet I30 into the opening I40 in the cupola or dome 130 and thence I downwardly through the spring controlled check valve I14 into the upper horiz'ontal conduit or passageway I15 in the tank, from whence it flows through the outlet I16 into the piping leading to the boiler. The feed water chamber is provided with an air vent I11 and the lower leg I12 of this An atmospheric relief line I85 serves to conpump. The condensate'is thus permitted to flow nect the upper portion of the condensate chamber I58 at a point above the check valve I59 with the highest point of one of the inlet chambers of the pump as, for example, the condensate fluid inlet chamber II as indicated in Figures and 13 of the drawings. breaking an undesired syphon eifect which will be described in connection with the operation of the pumping installation.

III

.In Figure 9 of the drawings there is diagraminatically illustrated certain instrumentalities by which automatic control of the pump is insured. A portion of the motor-which drives the pump is indicated at I08. 5 A portion of the return main of the vacuum heating system is shown at I89 and to this main is applied a vacuum indicator and vacuum controlled electric switch I90 of any conventional type. A float I92 is disposed in the boiler fed water chamber and is adapted to control the switch I93. The current main which supplies the motor I08 is indicated at I95 and may be provided with a master switch I96. The vacuum control switch I 90 and the float control switch I93 are each arranged in series with the motor I88 so as to individually control the opera tion thereof. The switches I90 and I93 may be thrown into and out of service by themanually operated switches I98 and I99. Another manu-'- Under normal operation of the system, theswitches I98 and I99 are closed and the switch 200 is open, thus establishing the automatic control of the pump driving motor I88. When the vacuum in the return pipes of the heating system I89 falls below the desiredpoint; the automatic switch I90 is actuated and the motor I 88 starts the pump in operation. Then if there is any liquid condensate in the tank it is withdrawn by the aspirating action of the priming water and both are returned to the priming water compartment I65, the excess water spilling over through the openings I1I into the feed water compartment I10 from which it is supplied to the left hand boiler feed pump side of the pump A through the proper passageways in the dome I30 and the outlet conduit l15'in the upper portion of the tank. If there is no liquid condensate in the system, or after the liquid condensate has been thus withdrawn, the suction side 80 of the pump withdraws air from the system and produces the desired degree of vacuum whereupon the vacuum regulator stops the motor and the pump. The air that is withdrawn from the system escapes through the vents in the priming water and feed water tanks.

On the other hand, when the water level in the feed water compartment I10 rises beyond the desired point, the flat valve I93 is actuated and the pump is started so as to deliver this excess feed water to the boiler. If, during this phase of the operation, the vacuum in the return system is already sufficient, suitable vacuum relief valves disposed in the return system will maintain the vacuum atthe proper degree.

In starting up the system after a period of idleness during which the heating system has become partly filled with accumulated condensate, the by-pass valve I is opened, connecting the closed, the resulting high level in the feed water compartment causing the float switch to start the This is for the purpose of directly through the valve controlled opening I18 into the feed water compartment and thence to the opening 182 into the left hand or feed water side of the pump and thence to the boiler. when the condensate in the heating system has been removed sufficiently to cause the level in the boiler feed water compartment of the tank to attain the proper point, the float control valve I93 will open. This method of starting the system has a great advantage since it is quicker to empty the return conduits of condensate in this manner than to attempt to create a vacuum in the .system first. -When the excess accumulation of by-pass valve- I80 is closed. The pump will then exhaust the'air from the heating system and produce the necessary partial vacuum and the unit 'will function automatically, as already described,

returning the water to the boiler when necessary and maintaining the vacuum in the system between fixed limits. i

The system, when desired, can be operated without vacuum as a gravity return system under atmospheric pressure. For example, during night operation when flres have been banked, the vacuum control is cut out, but the float control is left in operation and the valve I80 is opened. During this period the valve H8 is closed and the condensate is returned to the boiler through the left hand or feed waterside of the pump. When a suificient amount of condensate fllls the system the float valve operates the pump until the water has fallen .to the proper level. when the pump is cut off.

Since this automatic operation does not occur very frequently during this period when the fires are banked and very little steam generated, there would be danger that the cooling of'the system would produce a back vacuum which would draw off, not only the condensate, but the priming water for the left side of the pump. Thecheck valve I5I should take care ofthis-situation but additional precautions are necessary in case of] matter how the pump is employed. The atmosphere relief line I effectively prevents the syphoning off of the necessary priming water,

' especially in cases where a back vacuum may occur on either side of the system and in the event that the check valve I59 and I5I should leak. Should such leakage occur through any or all of the check valves the water can only flow back into 60 the system to the level of the relief pipe I85 where atmospheric air from the chamber I65 would flow back through the conduit I28 through the impeller passages 89, and 9I and into the 'condensate intake chamber II5 of the pump to which the relief line I85 is connected. Thus the priming water supply is trapped and can onlybe drawn off by opening a suitable drain (not shown) in the chamber I65.

Although the various operations of the system have been described in connection with the pump A only, it will be readily understood that the operation is very similar when both pumps A and B are provided, the apparatus being duplicated on each side of the installation as indicated in Figure 7 of the drawings. When both sides of the apparatus are in operation the valves I59 and I'll will open and close automatically according to whether or not there is enough condensate to keep them both in operation; in any case, the valves closing on the side of the pump that is not receiving condensate. When only the pump on the right hand side of the center line z-x is operating, then the valve I" on the left will close against the boiler pressure and the left hand valve l 59 will close against the vacuum. This feature permits making repairs on either pump unit while the other is operated; the valves 3 and I34 being closed during these operations. By locating the high and low water levels in the priming water compartment I85 and the boiler feed water compartment I10 so that enough head on the pump suction is obtained, condensate of described will be apparent. With this type of pump a high degree of exhaustion can be obtained and this more rapidly than in prior constructions. Greater power economy can also be attained because the vacuum side of the impeller does not have to work against boiler pressure or against devices requiring a high pressure to produce the vacuum. Furthermore, the boiler feed side of the pump'returns water only against the boiler pressure, and is not concerned with pumping air. The present arrangement also has the advantage of greater flexibility in its various operations and in its protection against. loss of priming and sealing water. a

In Figure 1'7 there is illustrated an embodiment of my invention which employs an impeller which is the exact equivalent of the one used in the vaccum heating system just described and centrifugal single fluid pump" on the left hand side thereof as seen in this figure. The multiple fluid suction pump side 80 of the impeller is provided with the propelling or aspirating fluid conduit 80 which leads to the short buckets 01 and the aspirated fluid enters the annular passageway 30 through the holes 0| and is drawn through the outer buckets 83 and thence through the mixing portion of the impeller and outwardly into the volute chamber of the'casing.

The casing of this pump is indicated generally by the reference character 20! and is preferably composed of the upper casting 202 and the lower casting 203, the latter being provided with the suitable base 204. The main inlet conduit 205 of the pump is preferably of the shape indicated, the inlet opening being higher than the center intake passageways I1 of the rotary pump section 12. The main volute impeller chamber 201 is provided with the outlet 200 through which the fluid is centrifugally ejected. A priming water compartment 2i0 is provided on the right hand side of the 'pump and this compartment is always filled with priming water to a level indicated by the line H. The compartment 2l0 is provided with an air vent 212 which may serve to exhaust entrapped air or gases to the atmosphere, or may be connected to a suitable container in case these gases are to be collected. The priming water in the chamber or compartment 2|0, is, of course, free to pass into the central conduit of the right hand side 80 of the impeller and is also in communication with the volute chamber 2| 4 of the right 'hand' pump section. The priming water chamber H0 and the volute impeller chamber 2 are both sealed off from the intermediate aspirated fluid inlet chamber 215 by the sealing and bearing rings 2I5 and 2H fitted to suitable seating surfaces on the casing and the impeller. This inlet chamber is connected by means of the pipe 2I8 with the inlet conduit 205, the mouth of the pipe being controlled by the float valve 219 occupying the chamber 220 in the wall of the conduit 205which connects with the interior of the conduit by means of the narrow passageway 22I.

The operation of this apparatus as a selfpriming pump will now be described, a body of priming water being also retained to the level zz bymeans oi the elevated inlet conduit 205, even though leakage should occur around the clearances between the left hand pump section 10 and the right hand pump section 80. Thus the right hand portion of the pump is always primed and the priming water, being circulated continuously from the compartment 2l0 through the rotor or impeller through the volute.cham-' her 2 and back to the chamber 2"), acts as an aspirating medium in drawing any air or gases which maybe in the intake conduit 205'through the pipe 2I8,the chamber 2l5, the rotorof the pump 80 and thence into the priming water compartment 2|0 to escape through the opening 2I2. As the water level in the intake 205 rises due to the creation of a. vacuum above this water level the left hand side 10 of the. pump will receive water and the continued rising of the waterin the inlet 205 will cause the float valve 2l9 to close the opening in the pipe 2l8 and prevent the by-passing of the water through this passageway and mingling with the priming water.

This arrangement can also be used as a suction operated sewage ejector,. for certain types of chemical pumps, for raising liquid containing entrained gases and in similar connections.

In Figure 18 of the drawings there is illustrated an arrangement in which either a single suction or double suction pump such as described in the earlier portions of the present speciflca tion may be employed. This pump is indicated generally by the reference character 225, the aspirating medium admitted through the manifold 226 drawing the fluid through the pipe 221 controlled by the valve 228. The pump outlet conduit is indicated at 229. A separating tank 230 is provided which also constitutes a reservoir for the priming fluid. This fluid may be admitted from a suitable source through opening 232 controlled by the valve 233 which is actuated by the float 234, the outlet 235 of the tank being 7 connected with the priming water manifold 226 of the pump. The outlet manifold 229 of the, pump, through which the mixture of priming and aspirated fluids is ejected, is connected as at 231 with the upper portion of the tank 230 and the separated gaseous fluids pass off through the-out-,

necessary air pressure to operate a pneumatic sewage ejector, a portion of which is indicated pressure may be applied to the upper portion of the tank by actuation of the valve 26!.

A float 263 is provided .within the tank 25I and is connected by means of the linkage 264 with an electrical switch 265, the contacts of which it is adapted to close in order to start the motor operating the pump 225 when the receiver 25| fills to a predetermined level. When the float switch is actuated; the pump 225 starts, compresses the air and delivers the air and the propelling water to the tank 230 wherein they are separated and the compressed air passed through the conduits 239 and 260 and the valve 2!. to the sewage receiver 25l from whence the sewage is ejected through ,the'check valve 256 and into the street sewer. The valves 228 and 25l may be electrically operated so as to open and close simultaneously with the starting and stopping of the pump 225 controlled by the float operated switch 265.

From the foregoing description; it will be seen that'by means of my invention there have been provided several novel arrangements of pumping systems embodying the principles of my invention and certain other embodiments have been suggested herein. It will be understood that varvapors which might be in the return main of the heating system. 1

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. A centrifugal pump comprising, in combination, a casing enclosing an annular volute impeller chamber having a discharge opening at its periphery, a plurality of annular intake chambers spaced axiallyfrom said impeller chamber and from each other by bearing ring seats, a rotary impeller having radially extending vanes and shrouds disposed. within said impeller chamber, said impeller being extended axially to form a tubular portion directed toward said intake chambers, bearing ring seats formed upon said impeller, and bearing rings between correspond-.-

ing seats on the casing and the impeller, a partition dividing the radially extending .portion of the impeller into two compartments and ,ex-,

and an axial extension in each direction therefrom, spaced annular chambers in said extensions providing intake chambers for propelled and propelling fluids, a rotary impeller having an axial hub and a centrally disposed radial enlargement comprising side-shrouds and radial vanes connecting said shrouds to provide a plurality of fluid compartments, said shrouds being extended axially in each direction to form tubular impeller portions occupying the axial extensions of said chamber, a pair of partition members similar in configuration to said shrouds, having spaced radial portions intersecting said'vanes and spaced from said shrouds, said partition members extending axially to form annular inlet conduits for propelling and propelled fluids respectively between themselves and said hub and said shrouds, said conduits being connected respectively with said intake chambers, the central radial portions of said partitions being of less, extent than the corresponding portions of said shrouds whereby the propelling fluid admitted between the partitions will efiectively aspirate the propelled fluid admitted between the respective partitions and side shrouds.

3. An impeller for centrifugal aspiratory pumps comprising, in combination, an axially elongated hub, radial vanes disposed around said hub at the central portion thereof, lateral shrouds connecting said vanes and extended axially of said impeller in each'direction to form tubular impeller portions surrounding said hub, a tubular partition dividing each of said tubular impeller portions into inner and outer annular channels, said partitions flaring radially adjacent the center of said impeller, intersecting said vanes, and extending for a short distance between said laterally spaced shrouds to form with said vanes a series of nozzles for impelling fluid, said vanes and said shrouds providing a series of nozzles for the propelled fluid upon each side of said first named nozzles, and providing mixing jets outwardly beyond said partitions.

4. An impeller for centrifugal aspiratory pumps comprising, in combination, an axially elongated hub, radial vanes disposed around said hub, spaced lateral shrouds connecting said vanes, one of said shrouds extending axially of said impeller to form a tubular portion of said impeller surrounding said hub, a tubular partition dividing said tubular impeller portion into inner and outer annular channels, said partition flaring radially adjacent the vaned portion of said impeller, intersecting said vanes, and extending between said laterally spaced shrouds to form with said vanes a series of rotary nozzles for aspirating fluid, said vanes and shrouds providing a. series of rotary nozzles for the aspirated fluid laterally of said first namednozzles, and providing mixing nozzles outwardly beyond the periphery of said partition. I

5. An impeller for centrifugal aspiratory pumps comprising, in combination, an axially elongated hub, radial vanes disposed around said hub, spaced lateral shrouds connecting said vanes, one of said shrouds extending axially of said impeller to form a tubular portion of said impeller surrounding said hub, a tubular partition dividing said tubular impeller portion into inner and outer annular channels, said partition flaring radially adjacent the vaned portion of said impeller, intersecting said vanes, and extending between said laterally spaced shrouds to form with said vanes a series of rotary nozzles for aspirating fluid, said vanes and shrouds providing a series of rotary nozzles for the aspirated fluid laterally of said first named nozzles, and providing mixing nozzles outwardly beyond the periphery of said partition, inlet openings in the laterally extended portion of said shroud for admitting the fluid to be aspirated to the outer one of said annular channels, and another opening in said impeller for admitting aspirating fluid to the inner one of said channels.

6. An impeller for centrifugal aspiratory pumps comprising, in combination, an axially elongated hub, radial vanes disposed around said hub, spaced lateral shrouds connecting said vanes, one of said shrouds extending axially of said impeller to form a tubular portion ofsaid impeller surrounding said hub, a. tubular partition dividing said tubular impeller portion into inner and outer annular channels, said partition flaring radially adjacent the vaned portion of said .impeller, intersecting said vanes, and extending between said laterally spaced shrouds to form with said vanes a series of rotary nozzles 'ior aspirating fluid, said vanes and shrouds providing a series of rotary nozzles for the aspirated fluid laterally of said first named nozzles, and providing mixing nozzles outwardly beyond the periphery of said partition, the outer ends of said axially extending shroud and of said partition merging. together to seal the end of said outer annular channel, and inlet openingsfor admitting the aspirating and aspirated fluid to said channels.

7. An impeller for centrifugal aspiratory pumps comprising, in combination, an axially elongated hub, radial vanes disposed around said hub, spaced lateral shrouds connecting said vanes, one of said shrouds extending axially of said. impeller to form a tubular portion of said impeller surrounding said hub, a tubular partition dividing said tubular impeller portion into inner and outer, annular channels, said partition 1 flaring radially adjacent the vaned portion of said impeller, intersecting said vanes, and extending between said laterally spaced shrouds to form with said vanes a series of rotary nozzles for aspirating fluid, said vanes and shrouds providing a series of rotary nozzles for the aspirated fluid laterally of said first named nozzles, and providing mixing nozzles outwardly beyond the periphery of said partition, the outer ends of said axially extending shroud and of said partition merging together to seal the end of said outer annular channel,- inlet openings in the axially extended shroud forming the tubular impeller portion for admitting the fluid to be aspirated into the outer one of said annular.

opening at its periphery, a plurality of intake openings in said casing at points spaced axially from said impeller chamber, a rotary. impeller comprising a plurality of radially extending vanes and axially spaced shrouds joining the side edges of said vanes and forming the side walls of the greater portion of said impeller, at least one of said shrouds being extended axially to form an elongated tubular portion directed toward said intake openings, a partition conforming to the general configuration of said extended shroud, dividing the radially extending portion of said impeller into two compartments, and being extended axially and substantially coterminous with said'shroud extension to correspondingly divide the tubular portion of said impeller into parallel concentric conduits, and sealed connections between said conduits and said respective intake openings. I

9. A centrifugal aspiratory pump comprising, in combination, a casing having a centrally disposed radially enlarged volute impeller chamber, and an axialextension in each direction therefrom, intake openings through said casing leading into said axial chamber extensions for admission of the aspirating fluid and of the'fluid to be aspirated, a rotary impeller having a centrally disposed radial enlargement comprising side shrouds and radial vanes connecting said shrouds to provide a plurality of fluid compartments, said shrouds being extended axially in each direction to form tubular impeller portions occupying the axial extensions of said chamber, a pair of partition members similar in general configuration to said shrouds and having axially spaced radial portions intersecting said vanes and spaced from said shrouds, said partition members extending axially within and substantially coterminous with the tubular portions of said shrouds to form parallel concentric inlet conduits for the aspirating fluid and the fluid to be aspirated respectively, said conduits being connected respectively with said intake openings at each end of'said casing, the central radial portions of said partitions being of less extent than the corresponding portions of said shrouds,

whereby the aspirating fluid admitted between the partitions will effectively aspirate the fluid ially in opposite directions to form the tubular extensions of the impeller, a tubular partition substantially coterminous with and dividing each of said tubular impeller portions into parallel, concentric conduits for the aspirating fluid and the fluid to be aspirated respectively, said partitions flaring radially adjacent the center of the impeller, intersecting said vanes, and extending FRANK E. STELZER. 

